Some species will successfully shift ranges under climate change. Many will not.

Climate change.  Forest loss. Agricultural intensification.  Urbanization and policy change and international markets.  The list of factors that influence ecological networks (i.e. connectivity) over the long-term seems to be growing daily, and parsing out their individual influences on future species’ distributions is a complicated task.  It’s also a crucial one, however, given the need for realistic predictions on population viability for many species, and the need for land managers to make realistic decisions about land use policy.

In their recent paper in Landscape Ecology, Gimona et al. build on previous work (Gimona et al. 2012) that examines woodland network response to land use change by specifically considering how woodland networks may facilitate species range shifts under climate change, land use change, and varying dispersal abilities.

They used mainland Scotland as their study region and ran simulations based on four climate scenarios, four hypothetical dispersal distances, and an Agent-Based Model that represented different land managers’ behavior.  Their methods integrate land use science with landscape ecology, and represent the first of its kind to explicitly consider the land managers’ effect on landscape dynamics in the context of range shifts.

The results lead to some striking conclusions.  For species with shorter dispersal distance (<2km) – which includes many woodland plant species – woodland connectivity will not be enough to keep pace with climate and land use change, and species are vulnerable to being overtaken by the trailing edge of their habitat niche.  Mid-distance dispersers (2-5 km) will require the persistence of habitat patches as stepping stones as well as general woodland expansion to successfully disperse.  Land managers are likely to support the idea of maintaining habitat patches and stepping stones in general, but only if economically feasible.

Given that the pace of climate change is faster than any previously observed range shifts in history, these results are particularly relevant for managers and policy-makers to consider.  The decision to preserve connectivity or to convert or intensify remnant patches for agricultural use ultimately rests on managers, who must consider the financial benefit of each option.  Regardless of how land use changes, the authors suggest that the most viable option for limited woodland dispersers, including most plants, may in principle be translocation rather than woodland connectivity.